Problems with Protoss Physiology

In a recent SC2 Blizzard Q&A batch, there was an interesting point raised on the subject of how the Protoss obtain their nourishment.

Here's the direct quote:

5. What do the Protoss eat? (Where do they get energy and mass?) (starcraftcz.com)Protoss gain nutrition from sunlight, or at a pinch, moonlight (which is just reflected sunlight anyway) by absorbing through their skins. They can go for extended periods without absorbing sunlight. What little moisture they need is also absorbed through their skin.

This interesting new fact raises several problems (however hypothetical) about Protoss physiology.

By having Protoss obtaining their energy from the sun, we can assume that they mean the Protoss absorb energy from photons on the molecular level, and convert that electromagnetic radiation energy into chemical energy stored in chemical bonds which they later break to release the stored energy. A key consequence of absorbing energy from light is that you change the wavelength of the reflected light, resulting in a change in the colour of the reflected light.

In photosynthetic organisms on Earth, the dominant pigment used to absorb energy from light is chlorophyll, which absorbs most wavelengths of visible light except green, resulting in a green colour.

However, it seems impossible for this mechanism to work since Protoss skin is pale-ish, meaning that they reflect nearly all wavelengths of light and do not absorb substantial amounts of energy from light.

Also, another incongruous issue raised by making Protoss photosynthetic is that it means that they are autotrophs; organisms that derive energy directly from the abiotic environment and not from other organisms.

Why is this a problem? Well, for one thing, autotrophs are subject to different evolutionary pressures than herotrophs (On Earth, heterotrophs are just about everything except for chemoautotrophic archaebacteria {or whatever their name is nowadays} and photosynthetic organisms).

Autotrophs tend to be non-motile because they do not need to move around to find sources of energy (it's always shining down upon them or streaming out of undersea vents), and they certainly don't have to hunt down their meal (except for certain insectivore plants, but I digress...). Plants on our world do not move around or think or whatever because natural selection does not favor autotrophs that do so.

So, evolutionarily speaking, it does not make sense to have an autotrophic Protoss. All the traits of the Protoss suggest a predatory ancestry, like their communal hierarchy, their manipulative hands, their bipedal stance, etc.

On the other hand, there are already photosynthetic organisms on Aiur. The jungles are full of green 'plants' that quite resemble our own lethargic and stationary plants on Earth. Those plants have no use for pale skin, hands, brains, psionic storms, and so on.

Even the lore of the Starcraft universe contradicts the idea that Protoss could be autotrophic.

Despairing at last, the Xel-Naga focused their frustrated efforts on the most promising of their engineered worlds. Aiur, a massive jungle-world on the galaxy’s fringe, had borne a race of highly advanced beings.

These beings were incredibly adaptable to harsh natural conditions and climates. Their strength and speed were unparalleled amongst the other races known to the Xel-Naga. The race had even developed a rudimentary tribal society based upon group-hunting and warrior rule. However, their most distinct aspect was that they communicated with each other through a very complex method of instinctive telepathy, allowing them to operate communally with striking efficiency. The Xel-Naga were pleased with the progress of their latest creation and conceded that the new race was the first of all their experiments to evolve beyond the feral constraints of baser life-forms. To signify their ascension in the galactic order, the Xel-Naga gave the new race the name of Protoss, or the First Born. The early Protoss lived in harmony and seclusion upon the world of Aiur for hundreds of generations, never knowing of the Xel-Naga who watched over them from afar.

There you have it, right from the original grail of SC's back-story itself. The Protoss were hunters, not some plant or whatever.

So, anyways, I hope that my long boring post will generate some discussion, and hopefully all the replies won't be "lol iz just a game blimey!1".

Note: Yes, I'm probably reading too deep into this, but hey that's the kind of stuff I like: totally useless and tangential. :3Plus, the idea of the Protoss being autotrophs bugs the hell out of me. C'mon, plants are lame.

Note#2: Damn TL.Net screws up my formatting.

Note#3: I don't pretend to know everything about biology or xenobiology (is that even a field?), but I'm just basing what I've written on what I've read in books and what not.

I actually really enjoyed reading this and the points you raised. As you say, inconsequential in the grand scheme of things but at least to me, these things are fun to talk about. The part about skin color, absorption and reflection made me think "oh shit I think you're right hahaha".

Btw about the evolutionary pressures part, werent Protoos created by the Xel'Naga? (My SC knowledge on lore is patchy at best, so I could very well be wrong) If they had suddenly appeared out of thin air then they dont have to be in line with evolutionary processes.

I believe you're missing Blizzard's whole point. They may have been hunters, but as evolution absolved them of their mouths and vocal cords in favor telepathy generated by their highly potent psionic brains, it absolved them of the primitive means of nutrition for auto-sustainment (ie mammals way of feeding). Protoss need such an infinitesimal portion of mass/energy, that sunlight and moisture will be enough. The highly potent flow of psionic energy, generated from their Khaydarin Crystals, Pylons, Nexuses and whatnot is almost enough.

So I believe that the current Protoss specimen is actually more evolved than your initial plants. They have the "purity of form" (opposed to Zerg's "purity of essence"), thus they are almost un-contained by any physical boundaries.

The part about light wavelengths is a slap in Blizzard's face (the more veritable one, at least in my eyes)

Except they didn't suddenly appear out of thin air, they're engineered by the Xel'Naga, but their lives still have to run their course.

Way I see it the point is not whether "iz just a game" or "this doesn't match that" but there seems to be some kind of disconnect with the sc1 lore and this current lore (or crackpot idea made up on the fly, I don't know, certainly anyone coulda thought of photosynthesis). I've heard of the "how do protoss eat" being asked out of being nosy fans who want to rationalize everything about starcraft. Guess I just find this unassuring, just like the "3 templar make an archon" and the other thing (what was it again?).

On November 05 2007 02:22 minus_human wrote:I believe you're missing Blizzard's whole point. They may have been hunters, but as evolution absolved them of their mouths and vocal cords in favor telepathy generated by their highly potent psionic brains, it absolved them of the primitive means of nutrition for auto-sustainment (ie mammals way of feeding). Protoss need such an infinitesimal portion of mass/energy, that sunlight and moisture will be enough. The highly potent flow of psionic energy, generated from their Khaydarin Crystals, Pylons, Nexuses and whatnot is almost enough.

The part about light wavelengths is a slap in Blizzard's face (the more veritable one, at least in my eyes)

That is a valid point, but the original SC lore suggests that the Xel-Naga found the Protoss as a still rather primitive hunter-gatherer society that already had developed psionic capabilities (ie; a communal mind linkage).

They don't really give a solid timescale that would indicate whether or not the Protoss had the time to evolve photosynthesis between the time that the Xel-Naga appear in the Koprulu sector and the time of Starcraft.

But in all likelihood, it might have been the Xel-Naga that modified the Protoss to become autotrophic. While the lore mentions that the Xel-Naga imparted advanced technology to the Protoss, it doesn't even hint at modifying the cellular(?) metabolism of the Protoss. The Xel-Naga might have done this covertly, though this suggests that a huge aspect of Protoss's origins have never been revealed!

Wow, nice post! I agree with your point, but some (small) things are a bit off.

Like: "All the traits of the Protoss suggest a predatory ancestry, like their communal hierarchy, their manipulative hands, their bipedal stance, etc. "

1. predators don't always hunt in groups, and how does this lead into a communal hierachy? 2. they have manipulative hands and bipedal stance, which would evolutionary stand for intelligence and ingenuity. Due to weight of bigger brain and the ability to use your hands more effectively.

If they had claws for hands, the hunter aspect would be more in place.

These few point aren't really important, but I just wanted to add them to you beautifully composed post.

As stated, the evolution argument doesn't apply due to the artificial nature, or "intelligent design" (lol at blizzard), nature of the Protoss race, and for the colour of their skin, they might absorb mostly light outside the visual spectrum, such as infrared and ultra-violet, especially if their near-by suns are burning at a significantly higher or lower temperature than the sun.

The light problem is a big one. But for the evolution aspect, I would guess that they evolved from meat-eaters or whatever, that after a certain amount of time and technology, they either altered their own genes or bred themselves to be photosynthetic as a means of practicality.

Why should they be limited to the absorption of sunlight from only the visible spectrum? It radiates many more wavelengths than actually reach us through our atmosphere. They could absorb x-rays or radio waves through a means we don't understand. Also, absorbing energy like this could be far more efficient than the photosynthesis we observe here... the Protoss were engineered, after all.

'Group hunting' could refer to more of a fighting action. Almost all large land herbivores, while not autotrophic, don't actually "hunt" their food down but still fight amongst themselves... and it's been established by things like the Aeon of Strife that Protoss readily fought each other.

As far as their development of working hands, powerful brains and psionic ability, I think it's possible from an evolutionary standpoint that their own fighting could have driven their mutation. This idea isn't applicable over a short period of time, because the race would have to be fighting for a great deal of time to actually influence their own evolution into breeding warriors.

Also, do you think that the Protoss could have actually modified parts of their own physiology as a species after they developed the technology as heterotrophs?

I really like your OP, though I find trivial things like this fun as well.

On November 05 2007 02:43 hku wrote:they might absorb mostly light outside the visual spectrum, such as infrared and ultra-violet, especially if their near-by suns are burning at a significantly higher or lower temperature than the sun.

That still leaves some problems (thought more surmountable), since ultraviolet light is highly damaging to organic molecules and infrared is too low in energy to realistically fuel cellular processes. Also, the dominance of green plants on Aiur (Green jungle-planet) suggests that the planet orbits a star similar to our own Sun and at a similar distance.

Yeah, personally I thought the idea that the Protoss absorbed light to eat was pretty ridiculous... the obvious question would be, where do they get their nutrients? They clearly aren't rooted in the soil, so unless they have no metals in them (and their bodies catalyze their reactions how?) it makes absolutely no sense. I guess they are at a state now where they could dope their water (if they even drink water?), but prior to that?

And as stated, ultraviolet light is energetic enough to dissociate bonds, so their skin color is pretty whack. It's entirely possible that their sun's wavelength of maximum emission would be different than the Earth's, but as also already stated, Aiur is green.

Edit: And no pores would not help, the molecules have to absorb light to do anything with it.

With the absorbtion of other wavelenghts emerges another problem: Do protoss obsorb the communicational wavelenghts of terrans? Just imagine, a large protoss fleet is attacking a terran planet, and all the communications are down because the protoss absorb the wavelenghts of the radios etc.Anyways, it could of course also be other wavelenghts, but this would be physiologically unreal.

Come to think of it, remember dragonball Z ?? With the GREEN people from namek , they were just like this protoss story, they only drink water (only difference) because they feed themselves from the energy of their surrounding sun(s). The thing is, they were green, and had the ability to grow their arms back etc. Thought this was kinda funny, but lame in respect to the protoss, since SC should be on a whole different level than something like DBZ.

Oh, one other thing, if the Protoss are photosynthetic, you would expect evolution to select for skin porosity (mentioned above) and also external structures that maximize their body's surface area for light absorption.But then, a Protoss sprouting leaves would be quite weird. ;D

Edit:

And no pores would not help, the molecules have to absorb light to do anything with it.

I think he was referring to how pores aid in the gas exchange required for photosynthesis.